Children having severe functional disorders have a difficulty in making pleasant movements in or of their own body. Movements which are pushing or shearing directed towards gravity affect the building-up or development of the skeletal structure of human beings and animals. Generally, children having severe dysfunctions have not themselves the capability of providing such dynamical loads. The lack of such movements contributes to skeleton brittleness of such children, see Konieczinski, D. D., Truty, M. J., Biewener, A. A.: “Evaluation of a bone's in vivo 24-hour loading history for physical exercise compared with background loading”, J. Orthop. Res., 1998:16, pps. 29-37, and Knothe Tate, M. L., Knothe, U., Niederer, P.: “Experimental elucidation of mechanical load induced fluid flow and its potential role in bone metabolism and functional adaptation”, Am. J. Med. Sci., 1998:316, pps. 189-195. Children having these kind of damages also generally often have an increased general level of muscular tensions, i.e. a high spasticity which can result in muscles pulling joints out of correct positions. The hip joint is worst affected thereby. Hip joint luxation is a painful condition. Preventive medical treatment including frequent injections of the nerve poison Botox and surgical operations to prolong muscles and sinews must be used for children that can have by joint luxations.
Vibrations and other dynamic loads on the skeleton have in animal tests appeared to have a large effect on the building-up of the skeletal structure, see Jankovics, John: “The effects of mechanical vibration on bone development in the rat”, J. Biomechanics, 1997:5, pps. 241-150, Rubin, C. T., Hausman, M. R.: “The cellular basis of Wolffs's law”, Rheumatic Disease clinics of North America, 1988:14, pps. 503-517, and Rubin, C. T., Lanyon, L. E.: “Osteoregulatory nature of mechanical stimuli: Function as determinant for adaptive remodeling in bone”, J. Orthop. Res., 1987:5, pps. 300-310. In a small study of children having cerebral paresis an increase of their skeleton mass when exposed to vibrations has been demonstrated, see Ward, K. A., Alsop, A. W., Brown, J., Caoulton, J. E., Adams, M. Z., Mughal, M. Z.: “The effects of low magnitude, high frequency loading treatment on volumetric trabecular bone mineral density of children with disabling conditions”, Times Newspaper LTD, 4 Jul. 2002. Physiotherapist have in clinical practice used movements and local vibrations to achieve a reduction of spasticity. Thus, in the best cases it is possible to obtain both an increased skeleton mass and a reduced spasticity, in the same time as the children themselves have fun.
Generally all children, also children having a severely reduced functional ability, have a need to feel that they can affect their situation and to feel the happiness of movement.
In Läkartidningen, February 2003, an apparatus has been described that allows that “children having severe neurological damages can themselves jump, dance and rotate”. The apparatus acts by “hanging the child in a standing shell, a moulded plastic shell, in a rack including an instrument panel. The child is allowed to choose the music and can then himself/herself control and determine if he or she wants to jump, rotate, elevate or lower himself/herself in the same rhythm as the music—thus to dance”. Since such children often has skeleton brittleness, an advantage associated with the apparatus is said to be that when children “move against the gravity, it affects the skeleton and they obtain stronger skeletons”. Furthermore, it is said, as to the use of the apparatus for children having severe neurological damages: “By the fact that they can affect their situation—they can choose what they want to do and they can rotate and see what happens in the room —also their mental development is stimulated”.
In U.S. Pat. No. 4,418,911 a swingable platform for videogames is disclosed that is driven by a motor and is suspended in a surrounding support. In the published U.S. patent application 2002/0094867 a board, of the type skateboard, is disclosed which through a plurality of intermediate parts is movably attached to a base plate. The movement of the board is detected in order to show image sequences corresponding to the detected movements. In U.S. Pat. No. 5,112,045 a device for kinesthetic diagnosis and rehabilitation is disclosed that includes a rigid plate mounted to an inflatable toroidal element, in which the pressure can be controlled by a patient who is standing on the plate. The plate cannot be controlled to provide different movements but only a very limited setting in the vertical direction and different degrees of elasticity in relation to the base. In International patent application WO 02/053084 a device for vibration stimulation of the human body is disclosed that includes a vibrating platform having support handles. Such a platform can perform only a very limited movement in relation to the base.